User authentication is typically required when accessing services (such as digital wallets, websites, networks, applications, etc) and devices (such as smartphones, computers, etc.). Commonly deployed authentication methods include:                (a) password authentication;        (b) Iris authentication;        (c) Facial authentication;        (d) Voice authentication;        (e) Fingerprint authentication;        (f) Vein authentication; and        (g) Predetermined gestures.        
Each of the above-mentioned authentication means has its relative strengths and weaknesses for security, reliability and/or implementation. As such, difficulties often arise in deciding which is the most appropriate authentication means to use.
Biometric authentication methods are convenient since there is nothing to lose or to remember. However, in order for them to be highly secure, increased user effort is required to use such systems. For example, in order to successfully authenticate using an iris scan:                (a) the user device needs to be held the right way, the right distance, and for the right time; and        (b) the image needs to be taken with the right lighting, with the proper head pose and with the proper eye position.        
As such, multiple authentication attempts may be required in order to successfully authenticate. This process can be generally inconvenient and can lead to user dissatisfaction. This is particularly the case where the user is moving and/or is not in a well lit area.
In many instances, users may be less concerned with security (e.g., accessing gaming stats or viewing photos), while in other instances security is more important (e.g., purchasing something online or accessing email), and in some instances security is critical (e.g., accessing a bank account or access control to house/car).
Currently, each of these scenarios often requires the user to authenticate using the same biometric methods, requiring undue user attention and effort, which can cause annoyance in scenarios where security is not that important (e.g., in the first instance), whereas in more important security critical scenarios (e.g., in the last instance) the same biometric method is not sufficient enough.
The above difficulties may cause the devices to perform in a sub-optimal manner causing further frustration and dissatisfaction to the user.
Authenticating the user with an appropriate and most convenient Consumer Device Card Holder Verification Method (CDCVM) will be key to mobile payments.
It is generally desirable to overcome or ameliorate one or more of the above described difficulties, or to at least provide a useful alternative.